Institute of Electrical and Electronics Engineers
In the age of cloud computing data users while enjoying a multitude of benefits from the cloud (e.g. cost effectiveness and data availability), are simultaneously reluctant or even resilient to use the clouds, as they lose data control. In emerging information networks, it is crucially important to provide efficient search on distributed documents while preserving their owners' privacy, for which privacy preserving indexes presents a possible solution. An understudied problem for the techniques is how to provide differentiated privacy preservation in the presence of multi-keyword document search. The differentiation is necessary as terms and phrases bear innate differences in their semantic meanings.